A mitochondrial DNA variant, identified in Leber hereditary optic neuropathy patients, which extends the amino acid sequence of cytochrome c oxidase subunit I.
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Brown MD, Yang CC, Trounce I, Torroni A, Lott MT, Wallace DC
A mitochondrial DNA variant, identified in Leber hereditary optic neuropathy patients, which extends the amino acid sequence of cytochrome c oxidase subunit I.
Am J Hum Genet. 1992 Aug;51(2):378-85.
- PubMed ID
- 1322638 [ View in PubMed]
- Abstract
A G-to-A transition at nucleotide pair (np) 7444 in the mtDNA was found to correlate with Leber hereditary optic neuropathy (LHON). The mutation eliminates the termination codon of the cytochrome c oxidase subunit I (COI) gene, extending the COI polypeptide by three amino acids. The mutation was discovered as an XbaI restriction-endonuclease-site loss present in 2 (9.1%) of 22 LHON patients who lacked the np 11778 LHON mutation and in 6 (1.1%) of 545 unaffected controls. The mutant polypeptide has an altered mobility on SDS-PAGE, suggesting a structural alteration, and the cytochrome c oxidase enzyme activity of patient lymphocytes is reduced approximately 40% relative to that in controls. These data suggest that the np 7444 mutation results in partial respiratory deficiency and thus contributes to the onset of LHON.